An Innovative Damper for Subsea Pipeline and Jumper Vibration Controls

Abstract

Abstract Low hydrocarobon prices have raised concerns over the viability of offshore field development and maintenance over next several years. These oil and gas prices have called for engineering efforts to innovate new technologies to reduce the operational costs and improve the life span of the subsea exploration and production (E&P) systems in inhospitable environments like deep water. Subsea pipeline and jumpers are among these subsea E&P systems and it is crucial for operators to have these systems function in smarter and more efficient way, to adapt the inhospitable environment while generating profits. Due to their geometry and location, these pipelines are typically susceptible to vibrations induced by multiple factors, such as flow-induced vibrations (FIV) and vortex-induced vibrations (VIV). FIV and VIV can cause excessive stress on pipeline joints, thus limiting the operational lifespan of pipelines, specifically jumpers and risers. Every year, oil and gas operators spend significant amounts of money analyzing the cause and effect of these vibrations on the fatigue life of jumpers and pipelines, and installing traditional vibration mitigation devices like strakes and shrouds that have proven to be only partially effective. In most situations, these devices fail to suppress the vibrations and force operators to choke the flow from the well for safety, resulting in lost revenue. This paper introduces the pounding tuned mass damper (PTMD) - a novel device developed in a joint collaboration between OneSubsea and the University of Houston to absorb and dissipate the undesired vibrations in subsea pipelines and jumpers. The PTMD is based on principles of both the tuned mass damper and the impact damper. The tuned mass in the PTMD absorbs the kinetic energy of the structure and dissipates the absorbed energy through collisions on viscoelastic material. During development, detailed numerical analysis and experimentation were performed to study the effectiveness of the PTMD on the jumper. In the experiment, a full size M-shaped jumper was tested in both air and shallow water conditions for VIV at NASA's Natural Buoyancy Laboratory (NBL). The experiment also examined the robustness of PTMD for different frequency VIVs. Experimental results showed that the PTMD effectively reduced the in-plane and out-plane vibration of the jumper up to 90%. The observed reduction in vibration amplitude can reduce fatigue damage to jumpers, thus enabling operators to optimize spending on vibration mitigation devices, minimize lost revenues, improve system lifespan and availability, and enhance operational flexibility. Reduction in stress also means improved reliability and reduction in costs associated with inspection, maintenance, and repair of subsea jumpers and pipelines. These long-term financial benefits and ability to be installed on existing and new jumpers (pipelines) makes the PTMD a desired solution for vibration suppression in deep water environments.